California - Criteria: C (architecture/engineering)
| Jeffers, Robinson, House |
| Jensen, Cornelius, Ranch |
| John Muir National Historic Site |
| Johnson, Hugh Edgar, House |
| Johnson, J. Neely, House |
| Johnson-Taylor Ranch Headquarters |
| Johnston, Darius David, House |
| Johnston, James, House |
| Judah, Theodore, School |
| Judge Lee House |
| Judson Studios |
| Kaehler-Rector House |
| Kahn's Department Store |
| Karasik House |
| Kearney, M. Theo, Park and Mansion |
| Kee House |
| Kee, Sam, Laundry Building |
| Kelso Depot, Restaurant and Employees Hotel |
| Kenaston House |
| Kennedy Tailing Wheels |
| Kerckoff Building and Annex |
| Kern Branch, Beale Memorial Library |
| Ketchum, Billy, House |
| Keyes Bungalow |
| Key, George, Ranch |
| Killefer, Lydia D., School |
| Killingsworth, Brady, & Smith |
| Kimberly Crest |
| Kindel Building |
| Kindler, Paul, House |
| King City Joint Union High School Auditorium |
| Kingen Hotel |
| Kings County Courthouse |
| Kinsey, Martha, House |
| Knights Ferry |
| Knight's Foundry and Shops |
| Knipp and Stengel Ranch Barn |
| Kocher-Samson Building |
| Koerner House |
| Koshland House |
| Kosy Knook Court |
| Kotani-En Garden |
| Kottinger, John W., Adobe Barn |
| Kraemer, Samuel, Building (American Savings Bank/First National Bank) |
| Kraft, Herbert, Memorial Free Library |
| Kress, George R., House |
| Krotoszyner, Dr. Martin M., Medical Offices and House |
| Krough House |
| Krug, Charles, Winery |
| Kruger House |
| Kuchler Row |
| La Belle Tour |
| La Casa Alvarado |
| La Casa Primera de Rancho San Jose |
| Lacey, Friend, House |
| Ladies' Relief Society Children's Home |
| Lafayette Hotel |
| Lais, Charles, House |
| La Jolla Post Office |
| La Jolla Women's Club |
| Lake County Courthouse |
| Lake Norconian Club |
| Lakeport Carnegie Library |
| Lake Tahoe Dam |
| Lake Vernon Snow Survey Shelter |
| La Laguna de San Gabriel |
| La Loma Bridge |
| Landrum, Andrew J., House |
| LANE VICTORY |
| Lantarnam Hall |
| Lanterman House |
| Larkin House |
| Larkspur Downtown Historic District |
| Larsen Family House |
| Las Casitas Court |
| Las Flores Adobe |
| Lassen County Court House |
| Lassen Volcanic National Park Highway Historic District |
| Lathrop House |
| Laughlin, James H. and Frances E., House |
| Lautner, John and Mary, House |
| Lawrence Warehouse |
| LCS-102 (landing craft support) |
| LeConte Hall |
| LeConte Memorial Lodge |
| Lee, Don, Building |
| Leggett House |
| Leggett, Thomas H., House |
| Leib Carriage House |
| Leonis Adobe |
| Le Petit Trianon |
| Lettunich Building |
| Lewiston Historic District |
| Libby, Charles, House |
| Libby McNeil and Libby Fruit and Vegetable Cannery |
| Liberty Hall |
| Liberty Street Historic District |
| Lick, James, Mill |
| Lightship WAL-605, RELIEF |
| Lincoln Heights Branch |
Data from United States Park Service and Wikidata
